The present invention is in the field of endoscopes and, in particular, is directed to an endoscope which is easily adjusted after the flexible portion thereof is inserted within a cavity.
Endoscopes are well known in the art for examining internal human parts, such as mucous membrane, or, when combined with other instruments such as a forceps, for carrying out operations within a cavity of the human body. Typically an endoscope includes a flexible tube having a tip portion which may be controllably bent by a suitable manual operation carried out at the opposite end of the endoscope. The flexible tube with the tip thereon is inserted within a cavity and then the tip portion may be bent by manually operating a control at the opposite end of said endoscope to position the tip so that the desired mucous membrane part may be viewed. In such devices there is usually provided adequate braking means for holding the tip in the desired bent position. As will be literally apparent, in the absence of adequate braking means the tip would restore to its natural position which may not necessarily be the desired position for viewing a particular part of a mucous membrane.
If such braking operation is continuously applied, it would cause pain to those undergoing examination for obvious reasons. Therefore, it is also necessary and desirable to provide means for releasing the braking force when the operation is terminated so that the entire flexible tube including the tip thereof may assume a shape controlled entirely by the cavity. Thereafter, the endoscope can be easily removed from the cavity without pain. One such device which has been proposed for practical use in the field includes a clutching mechanism which is engaged to operate as a braking mechanism on the flexible tip and is disengaged to permit the flexible tip to assume a natural position resulting from the shape of the human cavity. However, fine adjustment of the tip is quite difficult with the latter apparatus because of the separation of the means for controlling the bending of the tip and the means for engaging the disengaging the clutch mechanism. For example, if one desires to make a fine adjustment of the tip direction when the endoscope is inserted and the clutch is engaged, one would be required to disengage the clutch and then alter the direction of the tip and subsequently engage the clutch. The disengagement of the clutch, however, will immediately permit the tip to freely assume its natural position. Consequently, fine adjustments become extremely difficult. To further complicate matters, the person operating the endoscope typically has only one free hand for operating the clutching and controlling mechanisms thereby increasing the difficulty of making a fine adjustment of the tip direction.